The Impact of Broad Bean Hull on Blood Glucose Control and Gut Health

Summary

This study aims to assess the effects of broad bean hull (BBH) consumption on blood glucose and gut health. Broad bean (Vicia faba) is widely cultivated in Scotland, with the UK being the most significant European producer. The seed coat (hull or testa) is removed during broad bean processing. This is a significant secondary product that is largely discarded. Preliminary work showed that this material is comparable to wheat bran and is rich in fibre (49%) and protein (18%). Additionally, it showed a rich phytochemical profile and lower fat and carbohydrate content than wheat bran. Experiments also showed that BBH inhibited the activity of alpha-amylase and alpha-glucosidase enzymes, suggesting anti-diabetic properties. Overall, these results showed that BBH is a secondary crop product having potential as a functional food for humans. Therefore, the objective of this study is to assess in vivo in humans the physiological and functional effects of BBH. Using an acute phase randomised controlled crossover design, the study will assess how consuming BBH fortified breads affects plasma glucose and gut health. The study will recruit 18 volunteers, normal-overweight, aged 18-75 years, who habitually consume low amounts of fruits and vegetables (≤3 portions/day). The volunteers will attend two identical stand-alone intervention sessions lasting three days each following the screening. The order of the intervention sessions will be randomised. On the day before each intervention session, the participants will provide a baseline faecal sample and have a continuous glucose monitoring sensor (CGMS) attached. They will be also be given a standardised dinner. On the next morning, following a 10-12 hr fast, an indwelling antecubital cannula will be inserted, and a blood sample will be taken for measuring baseline levels of metabolites. The volunteers will be given a standardised portion of the BBH or control bread to consume, and further blood samples taken for the subsequent four hours. Breath samples will also be taken at the same time points for measuring gastric emptying. The volunteers will be provided with all the meals for the rest of the day and the subsequent two days. These will include two portions per day of either the BBH or control bread. The meals will be standardised for energy and macronutrients. The volunteers will be instructed to return to the Human Nutrition Unit on the fourth morning and provide a second faecal sample and remove the CGMS. Blood samples will be analysed for systemic bioavailability and metabolism of test meal components, glucose regulatory hormones and breath samples for quantifying gastric emptying. The faecal samples will be analysed for gut bioavailability and metabolism of test meal components, microbial counts, composition, and water content.

Conditions

• Healthy
• Overweight

Interventions

OTHER

Experimental: Bean Hull Bread

The bean hull bread will deliver 21.96 g of fibre. Volunteers will consume a roll of bean hull bread (155g/portion) served with 25g of raspberry jam.

OTHER

Experimental: Plain Bread

The control bread will deliver 4.53 g of fibre. Volunteers will consume a roll of plain bread (122g/portion) served with 25g of raspberry jam.

Sponsors & Collaborators

• University of Aberdeen

  lead OTHER

Principal Investigators

• Madalina Neacsu · [email protected]

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2019-01-31

Primary Completion

2020-03-31

Completion

2020-03-31

Countries

• United Kingdom

Study Locations